Telescopic unipod



July 1958 c W. MLVISSER ETAL 2,844,905

TELESCOPI'C UNIPOD 5 Sheets-Sheet -1 Filed NOV. 21, 1952 m W TH a S N MSWU a VWWS jun W. Em 0 mr M w u, wfio M LL OAL fl BM. U. Q

July 29, 1958 c w. MUSSER ET AL 2,844,905

' TELESCOPIC UNIPOD Filed Nov. 21, 1952 5 Sheets-Sheet 2 23 FIG. 20

79 v 87 8O r 84 94 91 93 33 x j 17 FIG.

INVENTORJ 9 2 9 c WALTON MUSSER ALBERT BENDITT Y LLOYD. w. INSETTA 15 B ATTORNEYS;

July 29; 1958 w. MUSSER ET AL 2,844,905

' TELESCOPIC UNIPOD Filed Nov. 21, 1952 5 Sheets-Sheet 3 FIG. I2

III

INVENTORS O WALTON MUSSER I lr' |w"" gum ALBERT BENDITT LLOYD W. INSETTA 2 FIG. l3 awww aikwwwjmw ATTORNEYS:

31 1958 c w. MUSSER ET AL 2,844,905

TELESCOPIC UNIPOD Filed Nov. 21, 1952 5 Sheets-Sheet 4 INVENTORS' C WALTON MUSSER ALBERT BENDITT LLOYD W. INSETTA FIG. I? BY v 49 J.8QQ.M./O@W9-X4}(7MW ATTORNEYS:

July 29, 1958 c w. MUSSER ETAL 2,844,905

TELESCOPIC UNIPOD Filed Nov. 21, 1952 5 Sheets-Sheet 5 INVENTORS C WALTON MUSSER ALBERT BENDI B LLOYD W. INSE xfmamwmcyjm.

ATTORNEYS adjusted.

United tates Patent TELESCOPIC UNIPon c Walton Musser, Albert Benditt, and. Lloyd w. nae-ta,

Philadelphia, Pa., assignors to the- United States of The invention described herein maybe manufactured and used by or for the. Government for governmental.

purposes without the payment of any royalty thereon. The present invention relates to a'telescopic device and more particularly to a unipod of the kind especially use-.

7 ful as a support for portable weapons.

' Weapons 'of the kind stated above arev relatively light weight;- hence portable; and are designed to be firedjeither from oif-the-shoulder or from a prone position at anemp placement. In the latter case, the rifle isprovidedwith Z a combination of supports, such as'a un'ip'odand a bipod', which together form a tripod. .In mostcases,.the"bipodj is located in a position toward therear of "the 'rifief and. the unipod in aposition forwardly thereof." The'unipod' is usually made adjustable, that is, extendable by employingia plurality .of telescoping members, thereby to comp'ensate for elevating the rifle to an adjusted firing posi tion. If, however, the rifle is to be fired from the shoulder, the bipod can be quickly removed from the" rifle or otherwise pivoted to a, position out of the: way.. In

such case, the unipod'is useful as 'a handle for supporting and steadying the rifle. 4

"In spite'of the fact that many prior" art supports employing unipods have been quite successful, they still have been found to have various shortcomings. For

' example, in order to extend the telescopic members of the unipod for elevation adjustment purposes, most .de-

vices require the use of both hands of the operato'r one. hand for locking and unlocking while the other hand adjusts the components. In other cases, thepartsare complicated insofar as assembly and Ydisassemblyconcerned. Other devices are diificult tQ-maintainfin a locked, adjusted position. In others, not all of thetelee scoping members are adjustable to partly extended'positions but require. full ex t ension orwithdrawal thereof,

It is, therefore, a primary object of the present invention to provide an improved unipod construction which will overcome the above and other disadvantages of;

prior art 'unipods.

It is also an object of thep resent invention to provide forfirearms a unipod which canfbe qui ckly andeasily A'further object of the presentihventidnistoprovide for. a unipod. a simple means of adjustmentwith requires.

handv of the operatqrto eflect suchthe use of but one adjustment.

' I Still further, it is an object of the present invention to provide a unipod which ca'n'l'ae quickly and easily assem- I I bled: anddisassembled. 1 1 q Another object of the present invention is to provide a. positive locking means for the;telescopingfmembers of aunipod regardless of the adjusted position of the-mom hers. 1 v 7 Still another object of the present invention is to pro.-. -vide for theunipod= telescoping members an end: closure member which can be locked in place' thereby prevent.- ing-inadvertent removal or accidental: loss thereof;

,; I t.is another object of the'pre'sen. inve'ntion to provide most and the third alented Joly .29. 1.9.58

. 2 v for a firearm a unipod which is relatively simple, iniconv struction, eflicient in operation and inexpensive tomanufacture.

In accordance with the present invention, the unipod comprises four sleeves arranged in telescopic relation respectively one within the other. reference hereinafter, they have been termed, from within outward, the innermost, second, third and outermost sleeves. The innermost sleeve is, arranged for adjustment by rotating it with respect to the others, thereby tomove. it between a fully inserted position within the second sleeve and a substantially fully withdrawnposition therefrom. The third sleeve is slidable in a longitudinal direction within the outermost sleevefor adjustment to an extended position therefrom. 'Locking means is provided 7 to hold the third sleeve in an adjusted position within The novel features of the present invention, both as, V

to its organization andfmethOd, of. operation,; as well as, additional objects andfladvantag'es' thereof, will beunderstood better from the following description, whenread-iri-v connection" with the accompanying;drawings'in which 'a, single preferred embodimenhof .thepresent' invention is represented; I I

Fig; 1 is a side view of a firearm provided with..a com-v bination support including a unipod in accordance with the present invention and a biped, a portion of thefire-I arm being broken away; i

Fig. 2 is a front end view of the apparatus shown. in

Fig. 1, but with portions ofthe firearm. brokenaway;

Fig. 3 is a side .view similar to Fig. 1 but :,with other i portions of the firearm broken away, the firearm being.

shown" intwo different elevated positions'using, the. com-, bination support'as'a' tripod;

Fig. 4. is arear-view of a portion of. the apparatus shown e in Fig. 3, showing the relative positions of ,theunipodf and bipod members when thefirearr'n 'i'sused in an em placement;

' Fig. 5 is a side view of a portion of the apparatus shown i in Fig. l, the unipod being shown withits telescopic members disposed in 3 fully retracted position and used to support the firearm above the. ground;

Fig. 6 is a view similarto Fig. 5, but showing the uni pod disposed with the innermost sleeve partly extended Fig. 7. is a view simila'rto Fig. 5, but showing the, inner: sleeves disposed in'a partly extended position;

Fig. 8 is an enlarged fragmentary view of the unipod,:

partly in section, and with portions of the sleeve members broken away to show hiddenparts;

"Fig. 9 is asectional view of .theunipod' shown in Fig.

8,.taken along-the, line -9- -9. thereof;

' Fig. 10 is a sectional view similar toFig; 9 but-taken V alongxrthe line 10-910 of Fig.

Fig. 11 is a sectional view of a portion of the base of I I the unipod, takenialong the'line 11 11'of Fig: 8;

.Fig. I2 is a view similar to 'Fig. 8, 'as seen-along the line 1212. thereof;

Fig. 13 is; a sectional view ofaportion'of the -unipoif v showing the relative position ofv the telescopic members: the innermost sleeve being partly extended from the sec- 0nd sleeve; 7

- third sleeve;

Fig. 13A is a view similar to Fi'g'a13, but'showin'g the innermost sleevefully extended from thesecond sleeve;

-Fig. 14 is a sectional view, similar to Fig. l3,ishowing;; the relationship of the telescopic members preparatory to v the 'out'ermost'isleeve with the; t

looking or unlocking of For convenience of Fig. 15 is a view, similar to Fig. 8, showing the relative position of the telescopic members in the unlocked position of the outermost sleeve;

Fig. 16 is a sectional view of a portion of the base of the unipod and showing the end cap locked in place, the view being taken along the line 16-16 of Fig. 15;

Fig. 17 is a sectional view of an upper portion of the unipod shown in Fig. 15, illustrating the relative position of the telescopic members with the third sleeve being fully extended or withdrawn from the outermost sleeve and in an unlocked position;

Fig. 18 is a view similar to Fig. 17, but showing the third sleeve in locked engagement with the outermost sleeve;

Fig. 19 is a side view, partly in section, of an upper portion of the unipod showing the relative position of the telescopic members, the innermost sleeve being partly withdrawn or extended from the other sleeves;

Fig. 20 is a sectional view, taken along the line 2020 of Fig. 19, but showing only the innermost sleeve and a means of attaching the unipod to a firearm;

Fig. 21 is a sectional view of a portion of the unipod, taken along the line 2121 of Fig. 19;

Figs. 22 through 24 are a series of developed views of the upper threaded portions of the three inner sleeve membersv illustrating various steps in the process of disassembly of these members as follows:

Fig. 22 shows the locked position of the members, the innermost sleeve having been rotated to a fully inserted position within the second sleeve;

Fig. 23 shows the third sleeves thread portion moved rearwardly or downwardly to align it with thethread runout portion of the innermost sleeve;

Fig. 24 shows the third sleeves thread portion partly advanced into the thread runout portion of the innermost sleeve and the second sleeves thread portion in alignment with the thread runout portion;

Fig. 25 is a developed view similar to Figs. 22 through 24 but showing the relative positions of the threaded portions of the three inner sleeves, the third sleeve having been disengaged from its locked position with the outermost sleeve; and

Fig. 26 is a view, similar to Fig. 25, showing the threaded portions aligned to allow rotative adjustment of the innermost sleeve with respect to the other sleeves.

Referring more particularly to the drawings, wherein similar reference characters are used to designate corresponding parts throughout, the unipod 1 of the present invention is shown and described as part of a combination support for a recoilless rifle 3. The support comprises a combination unipod 1 and bipod both of which are mounted on the rifle and arranged in such a manner as to be adjustable with respect to each other and to provide a tripod type of support useful in emplacement firing.

The bipod The bipod 5 is of any suitable type and is pivotally mounted in the vicinity of the rear chamber of the rifle for adjustment between two different positions. In the one position, the legs 7 are disposed close to and parfllel to the chamber (see Fig. 1). In the other position, the legs are disposed laterally extended from and normal to the rifle (see Figs. 3 and 4). In the first-mentioned position, the bipod legs 7 are adapted to provide a shoulder support for the operator and the unipod 1 is disposed in a convenient position to provide a handle for supporting and steadying the rifle. In the second-mentioned position, the bipod legs 7 are arranged for adjustment to a spread apart position for placement on the ground, therebyto support the rear portion of the rifle above the ground, while the front portion of the rifle is similarly supported by the unipod 1. A bipod of the type referred to is shown, described and claimed in the copending application to C Walton Musser et al., Serial No. 321,961, filed concurrently herewith. Y

The unipod The unipod 1 of the present invention comprises a plu rality of sleeve members arranged telescopically respectively one within the other. The unipod is arranged for extension in an axial direction to permit elevation adjustment of the rifle when supported on the ground in the manner illustrated in Figs. 5 through 7 of the drawings, adjustment being accomplished through the telescopic arrangement of the sleeves.

In the particular embodiment shown, the unipod 1 comprises four sleeves or hollow cylinders 9, 11, 13, 15, otherwise referred to herein as the innermost sleeve 9, the second sleeve 11, the third sleeve 13 and the outermost sleeve 15.

The innermost sleeve The innermost sleeve 9 has the external surface thereof provided with one or more helical threads 17. The threads are terminated at the lower or base end 19 of the sleeve by an annular shoulder 21. Adjacent to the opposite or upper end 23 of the sleeve, a portion of the threads are widened by cutting away a part of the land separating two adjacent grooves, in the manner indicated at 27 and as best shown in the developed views, Figs. 22 through 26. At the upper end of each groove, the land on one side (the upper side as viewed in the developed views) is somewhat widened thereby to provide a stop 29. In other words, continuity of the groove is interfered with by the stop 29 for a purpose hereinafter to be explained. A partition or wall 31 (see Fig. 20) is provided on the interior of the innermost sleeve 9 adjacent to the upper end 23 thereof. The wall 31 extends diametrically across the sleeve and is provided with an axial bore 33 for receiving a capscrew 35. The upper end 36 of the sleeve bore beyond the wall 31 is adapted to receive a cylindrical stud 37 of a bracket 39 provided for attaching the unipod 1 to the rifle 3. Thus, with the stud 37 disposed within the upper end of the innermost sleeve bore, the capscrew 35 is inserted through the wall bore 33 and is threadedly engaged with a threaded bore 41 provided in the stud.

The second sleeve The second sleeve 11 comprises a hollow cylindrical member which is disposable about the innermost sleeve 9 and which is coextensive therewith. The sleeve 11 is cut away at its upper end 42 to provide two oppositely disposed ears or fingers 43 of arcuate cross-section. The inner surface of the sleeve including the fingers 43 is substantially smooth except for an inwardly extending helical rib 45 provided on each of the fingers 43, and an annular groove 47 adjacent to the lower end 49 of the sleeve proper. The ribs 45are of a size and are arranged in a manner so as to mate with the external threaded surface of the innermost sleeve 9. The exterior surface of the second sleeve 11 is of uniform diameter throughout the greater portion of the length thereof. The lower end wall portion 51 of the sleeve is somewhat enlarged or thickened thereby to enlarge the external diameter and provide a shoulder or cam surface 53 useful for effecting a locking operation to be explained later herein. In addition, a narrow annular shoulder 55 is provided on the exterior of the lower end portion 51 intermediate the cam surface.53 and the lower end 49 of the sleeve.

The third sleeve The third sleeve 13 comprises a hollow cylindrical member which is adapted for placement about the second sleeve 11. The third sleeve is of a length substantially equivalent to the length of the second sleeve as measured between the upper end 42 and a point immediately beyond the cam surface 53 on the lower end portion 51. In the assembled position of the second and third sleeves, the lower end 57 of the third sleeve is spaced from the annular shoulder 55 of the second sleeve toallow for limited longitudinal movement of the one vided on the external surfaces of: two

sleeve with respect-to the other. The inside diameter of the third sleeve is substantially uniform and: slightly larger-than the outside diameter of the, second sleeve except for a relatively small inside wall portion 59locateclatthe, upper end of, the sleeve. The upper end wall portion 59 is enlarged or thickened to provide an annular shoulder 61 on the inside of the: sleeve. The

shoulder 61 is cut. away at diametrically opposite pointsto provide axially extending grooves 62 of a size to re ceive the second sleeve fingers 43: with a'slidable fit. In

extending resilient fingers 67. A portion 69' of the ex- 7, I ternal surface of'the third sleeve at 'the lower end thereof, that is, atthe free ends. of the; fingers 67, is threadedv to serve: as partof'a locking arrangement. In addition thereto, two oppositely disposed. bosses 71 are also pr,ooppositely disposed fingers 67., Y I

' I f The outermost sleeve" heoutermost sleeve 15 is also; a hollow, cylindrical member and is of a length greater than the-lengths of each of the three inner sleeves. Theoutermostgsleeve 15 has an internaldiameterslightly larger than theexternal'diameter of the third sleeve 1-3 so-that itcan be disposed thereaboutwith a slidable fit. The, internal sur face 73 of the sleeve is threaded-complementaryfio theexternal threaded portion 69. of the third sleever To -g gether thethreaded; surfaces. 69, 73- of bothsleevesfunc.

' tion as a locking means for holding the twosleeves in a selected, extended position relative toreach othere The interior surface 73 is;cutaway alongiftslength; to provide; two oppositely disposed, axially extending grooves 755f or receiving the thirdsleeve s bosses -71. Thisarrangement prevents rotative movement of-the outermost sleeve 'with respect to, the third sleeve andserves-to effect: extension of the three out'er sleeves with respect to theinnermose The lower end 77 of theoutermost sleeve is; chamferedat.spacedintervals. along the :inner periphery to provides. plurality of. groovesorslots 79. The-lands... 80 between thegrooves are cut awayat the lowerendsthereof in a..manner. 'to provide, an annular channel/81: on the inside at the, lower end 7.7;of the outermostsleeve. The upper end 82. of the outermost sleeve. is.provided; with aninternal annu1an shoulder83 which serves as. astoptoprevent. separation of the third :sleeve from-the outermost sleeve.

sleeve.

Inaddition to thefourtelescopie .sleeves,.;therunip d. is provided, witha closure member.84. for.-the-lower..e ds.. ofv the. sleeves; The closure men1ber 84- comprises a: disc-like cap 85... having a. liollowfcylindrical .bfod y. por tion 87 extending from one side thereof- The cylindrical body portion .87- 'isl externallythreaded andrarran ged l mate with the internal-threaded surface 73 of theouter 'inostsleeve'15. Two oppositely disposed-aperturesi89 are provided in and; extend through the wall-ofthe-body portion 87'. A 1ocking{mer;nber;91,-comprising a-metalspring, "extends diametrically across,- the body portion 87 -a-nd has the ends 9,3trthereof extending through the apertures 8910 an extent: slightly beyond the outer threaded surface ofthe body portion. ThQjl'OQiClDg members cen-j ter fportion 941 is. arcuate in Shape aud has -the"apex or intermediate portion thereof arranged; to bea-rQagainst; the cap '85. with. the ends. 93.:normallyidisposedspaced from the. cap, in the mannerishown in --Fig-;18-,of;;the-; 76379 at,5the-.-lower endof'theoutermost sleeve. Thus, the

' addition, the remaining portions or segments of the shouldrawings. With this arrangement, the ends'ofthespriiig 91 can be stressed toward the cap within the. confines'of 7 the apertures. 89. e

. Assembly ofthe unipo d. In assembling the respectivecomponentsof the the following procedure may be. employed: The second sleeve 11 is inserted into the. third. sleeve 13. from the lower end SZ thGIGQf The fingers 43 of the second. 7

sleeve are disposed. withinjthe slotsor grooves] 62 of. the. third sleeve. to an extent as to align the helical 45., 63 of both sleeves reform a substantially continuous helical rib. In this aligned position of the helical. ribs, the relative positions of the twosleeves is such as. to. dispose the free ends of the third' sl'eeves resilient fingers 67 over the cam surface 53 so that they are biased out.-

wardly and extend ontothe lower end wallportion 51 of the second sleeve. 7 v v i The innermost sleeve 9 is then inserted into the second sleeve 11 from the latters lower end 49. The threads 17 of the innermost sleeve beingopen at the upper'e'nd' 23 thereof, the helical ribs 45, 63 are thenadvanced intothethreads with the ribs of the second sleeve first entering the thread grooves followed bythe ribs of the- Advancement of the innermost sleeve is third sleeve. continued enough to align and engage the ribs with the main portion of the threaded exterior of the innermostc sleeve and disposethe lower end- 19 of the innermost sleeve somewhat above the lower end'49' of the second sleeve. By so doing, an annular groove 47'provid'ed on the inner surface adjacent to the lower end 49 of the second'sleeve 11 will be exposed an amount sufiicient to' insertla resilient lock washer or split ring 95 in the groove; The'lock ring 95' extends inwardly an amount" sufiicient to interrupt the path of the innermost sleeve,

and function as a. stop, thereby to prevent removal of J the innermost sleeve'fr'omthe lower end ofI'the-second sleeve. The innermost. sleeve. 9 is then retracted into the third sleeve an amount suflicienttocansethe-third sleeve 13 to move longitudinally with respect to the secsleeve.

. The assembly of four sleeves may then be mounted on the rifle bydisposing the bracket stud 37' within the upper end of. the inner sleeve'bore and securing the parts together by'the capscrew 35-which is introduced'thro'ugh. the bore of the innermost sleeve; Once mounted on the rifle, the closure member 84 is then assembled on the lower end ofthe outermost sleeve; With the outermost sleeve unlocked 'from the third sleeve, the outermost sleeve is moved 'as far as possible toward the upper ends of the other sleeves. In this. position, the. outside j diameter of theit'nird sleeve being slightlysmaller thanv the inside diameter"offthecl'osure member'.cyli'ndricali body portion 87, the closure, member is 'placed' over. and pressed against the lower end 5.7 of the thirdfsleeve in a manner to bias the spring ends 93 toward the. cap

Biasing the spring. inflthis m'anner; allows/the. cap to be threadedly engaged, with. the outermost fsleeve since the spring ends willibe ina positionto. rotate freely within the. channel 81 at the. lower end 77 of the outer- The closure member is then turned or most sleeve. V screwed into the. lower end of the outermostsleeve 15 backedolf an, amount sufiicientto cause the ends; 93 [of the 'springtov fall within diametrically. oppositeslots;

7 Closure member is securely fastened in place and locked against removal oraccidental turning;

Once assembled in the manner described above, the outermost sleeve 15 is locked in a position to secure it against longitudinal movement with respect to the third sleeve 13. This is accomplished by rotating the outermost sleeve counterclockwise thereby to cause the ribs 45, 63 of the second and third sleeves to follow the threaded exterior of the innermost sleeve 9. In so doing, the ribs will be guided into alignment and, simultaneous therewith, cause the third and outermost sleeves to move downwardly with respect to the second and innermost sleeves. The downward movement of the third sleeve will move the resilient fingers 67 over the second sleeves cam surface 53 and bias the fingers outwardly into engagement with the threaded interior of the outermost sleeve to lock the outermost sleeve in place.

Operation In use, the unipod of the present invention will be found to operate as follows: starting from a fully inserted position, as illustrated particularly in Figs. 1, 5, 8 and 12 of the drawings, in which position the outermost sleeve 15 is locked against movement with respect to the third sleeve 13, the unipod 1 is extended in one respect by rotating the outermost sleeve in a counterclockwise direction. Rotation in this manner will cause the ribs 45, 63 of the second and third sleeves to follow the helical threads 17 of the innermost sleeve and effect the emergence of the innermost sleeve from the upper ends of the other three-sleeves, in the manner shown in Figs. 6, 13 and 19 of the drawings. The extent of withdrawal in this manner is limited by the ribs engaging the annular shoulder 21 at the base 19 of the innermost sleeve, as shown by Fig. 13A of the drawings.

In another respect, the unipod may be extended by unlocking the third and outermost sleeve members and sliding them longitudinally with respect to each other. In order to do this, it is necessary that the innermost sleeve be fully retracted or inserted within the second sleeve. This is done by rotating the outermost sleeve clockwise until the ribs 63 of the third sleeve engage the widened land 29 providing a stop at the upper end of the inner sleeve, the position as shown particularly in Figs. 8 and 22 of the drawings. While in this position, the outermost sleeve is pulled downwardly to move the outermost and third sleeves longitudinally with respect to the second and innermost sleeves, thereby to align the ribs 63 of the third sleeve with the run-out thread groove adjacent the stop 29 at the top of the innermost sleeve, as shown in Figs. 14 and 23 of the drawings. Further clockwise rotation of the outermost sleeve will advance the third sleeve ribs into the run-out groove (as shown by Fig. 24 of the drawings) and simultaneously therewith draw the outermost and third sleeves upwardly with respect to the second and innermost sleeves. The widened threads in the vicinity of the cut-away land 29 at the top of the innermost sleeve allows the ribs 45 of the second sleeve to enter the cut-away section (as shown in Fig. 25 of the drawings). In so doing, the third sleeve is permitted to move upwardly with respect to the second sleeve an amount sutficient to remove the threaded ends of the third sleeves fingers 67 from the lower end wall portion 51 and beyond the cam surface 53 of the second sleeve, while the inner sleeve 9 is prevented from being more fully inserted by the lock ring 95 located at the bottom of the second sleeve 11. In this position, the fingers 67 are no longer biased outwardly and consequently are not engaged with the threaded interior surface 73 of the outermost sleeve. This position is shown particularly in Figs. 15 and 17 of the drawings. In other words, the third and outermost sleeves are no longer in locked engagement, and thus they can be slidably moved longitudinally with respect to each other. Withdrawal of the third sleeve from theupper end of the outermost sleeve is limited by the bosses 71 of the third sleeve engaging the internal annular shoulder 83 at the upper end of the outermost sleeve. Withdrawal of the assembly of the three inner sleeves from the lower end of the outermost sleeve is prevented by the closure member 84. Once the third and outermost sleeves have been adjusted in position relative to each other, the sleeves may again be locked in position by rotating the outermost sleeve in a counterclockwise direction in the manner heretofore explained.

Summary From the foregoing description, it will be recognized that the unipod of the present invention provides an assembly which is quickly and easily adjustable. Two separate and independent means of adjustment are provided whereby to etfect correction for elevation of the article supported thereby. By the one means, elevation may be adjusted quickly to the approximate height after which the other means may be used to correct for minor variations. As a safety measure, the parts are arranged in such a manner that adjustment cannot be effected at the same time by the rotative and sliding movements aforementioned. In other words, the outermost sleeve must be in an adjusted, locked position with respect to the third sleeve before adjustment can be accomplished by rotating the innermost sleeve. On the other hand, the outermost sleeve cannot be unlocked for adjustment before the innermost sleeve is rotated substantially to a fully retracted or inserted position within the second and third sleeves. With this arrangement, positive and accurate adjustments can be made.

Locking and unlocking of the outermost sleeve is accomplished as a function of the interaction of the second and third sleeves by means of which the threaded ends of the third sleeve fingers 67 are biased into engagement with the threaded interior surface of the outermost sleeve. As a result of such an arrangement, the outermost sleeve can be adjusted to any selected position with respect to the third sleeve, that is, in a longitudinally extended sense. Biasing of the third sleeve fingers outwardly is effected by longitudinal movement of thersecond sleeve with respect to the third sleeve so as to cause the fingers to ride over the cam surface 53 and onto the lower end wall portion 51 of the second sleeve. Relative movement of the second and third sleeves can only be accomplished when their respective ribs 45, 63 are located in the vicinity of the cut-away or widened portion of the threads at the upper end 23 of the innermost sleeve 9, in the manner described above and as particularly shown in the developed views of the drawings, Figs. 22 through 26. It will be observed, however, that mere withdrawal of the innermost sleeve by rotating the outermost sleeve will not unlock the outermost sleeve for adjustment. The stop 29 at the upper end of the innermost sleeve necessitates a longitudinal sliding action of the second and innermost sleeves with respect to the third and outermost sleeves before the parts can be further rotated to an unlocking position. This has been so made in order to prevent collapse of the unipod from an adjusted position of the third and outermost sleeves should an operator be using the innermost sleeve to adjust for height and not realize the relative positions of the third and innermost sleeves.

' It should be understood, however, that while the present invention isparticularly adapted as an adjustable support for firearms, it may well be applied to other applications wherein similar problems are met. Although a single, preferred embodiment of the present invention has been shown and described, it will undoubtedly be apparent to those skilled in the art that many other forms thereof, as well as changes in the particular one described, are possible within the spirit of the invention. For example, the means for locking the third and outermost sleeves against movement may comprise a friction means rather than .the interengageable thread means described tively one within the other, the external surface of said first sleeve being threaded throughout the greater portion 7 of its length, the cylindrical surface of said second sleeve being cut away to provide at least one finger extending longitudinally from an end thereof, the inner surface of I said finger being provided with a rib disposed in threaded engagement with the threaded surface of said first sleeve whereby said first sleeve is adapted for rotatable adjustment longitudinally with respect to said second sleeve between a position fully inserted within said second sleeve to a position substantially withdrawn therefrom, a portion of the inner surface of said third sleeve adjacent the end thereof respectively associated with said second s'leeves finger being provided with an annular shoulder which has at least one portion cut away to provide a 1ongitudinally disposed groove, said second sleeve finger being disposed within said groove whereby said second and said third sleeves are slidably adjustable in a longitudinal.

direction with respect to each other, said third sleeves annular shoulder being provided with thread means disposed in threaded engagement with said first sleeves threaded surface, the opposite end of saidsthird sleeve being cut away to provide at least one resilient longitu 'dinally extending finger, locking means extending radially outwardly from the free end of said finger, at least one boss on the outer surface of said third sleeve, said fourth sleeve having locking means on the inner surface thereof disposed complementary to said fingers locking means, at least one longitudinally extending groove on the inner surface of said fourth sleeve, said third sleeves boss being disposed within said groove, and biasing means carried by said second sleeve urging said third sleeves resilient finger outwardly into locking engagement with said fourth sleeves locking means.

2. The invention as defined in claim 1 wherein said second sleeves rib and said third sleeves thread means are in alignment to form a continuous thread portion engaged within the same thread groove in said first sleeve.

3. The invention as defined in claim 2 wherein .-a portion of the thread of said first sleeve adjacent to the end of said first sleeve which is associated with said second sleeves extension is cut away to allow limited longitudinal movement of said third sleeves thread means with respect to said second sleeves rib and said first sleeve.

4'. The invention as defined in claim 3 'wherein'said biasing means comprises an annular raised portion on the outer surface of said second sleeve, said raised portion being disposed in a position to bias said resilient finger outwardly in response to longitudinal movement of said second sleeve relative to said third sleeve in the one direction and to release the bias on said resilient finger in response to longitudinal movement of said second sleeve relative to said third sleeve in an opposite direction.

5. The invention as defined in claim 1 and wherein said unipod includes a removable closure member'for said sleeves, said closure member comprising a disc-like cap having a cylindrical body portion, the end of, said fourth sleeve disposed adjacent to said third sleeve resilient fingercomprising a base 'end, complementary, at-

taching means being provided respectively on the external surface of said cylindrical body portion and on the interior surface of said fourth sleeve base end.

6. The invention as defined in claim 5 and wherein said attaching means comprises complementary threads on said closure member and on said fourth sleeve, .and wherein locking means is provided on said closure member and said fourth sleeve to secure said closure member in place. 7

References Cited in the file of this patent UNITED STATES PATENTS 192,600 Ryan July 3, 1877 608,850 Folmer Aug. 9, 1898 959,291 Benet et a1 May 24, 1910 1,593,217 Lucker July 20, 1926 1,829,662 Krenzke Oct. 27, 1931 2,217,533 Wolarsky Oct. 8, 1940 2,472,804 Bird June 14, 1949 FOREIGN PATENTS 692,032 France July 28, 1930 172,279

Switzerland Dec. 17, 1934 

